diff --git a/examples/ontology_reasoning.py b/examples/ontology_reasoning.py
index c48f655b..8b3ebf5a 100644
--- a/examples/ontology_reasoning.py
+++ b/examples/ontology_reasoning.py
@@ -97,7 +97,7 @@
 L = OWLClass(IRI(NS, 'L'))
 M = OWLClass(IRI(NS, 'M'))
 N = OWLClass(IRI(NS, 'N'))
-O = OWLClass(IRI(NS, 'O'))
+O = OWLClass(IRI(NS, 'OO'))
 P = OWLClass(IRI(NS, 'P'))
 Q = OWLClass(IRI(NS, 'Q'))
 R = OWLClass(IRI(NS, 'R'))